﻿using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Configuration;
using System.Data.SQLite;
using System.IO;

namespace DBUtility
{
  /// <summary>
  /// Copyright (C) 2011 WinformGeneral 
  /// 数据访问基础类(基于SQLite)
  /// 可以用户可以修改满足自己项目的需要。
  /// </summary>
  public abstract class DbHelperSQLite
  {
    //数据库连接字符串(App.config来配置)，可以动态更改connectionString支持多数据库.		
    public static string connectionString = PubConstant.ConnectionString;
    
    //public static string connectionString = "data source=Student.db;version=3;";
    //public static string connectionString = ConfigurationManager.ConnectionStrings["sqlConn"].ConnectionString;


    public DbHelperSQLite()
    {
    }
    #region 2018新建方法
    /// <summary>
    /// 创建数据库
    /// </summary>
    /// <param name="file">数据库名</param>
    public static void createDd(string file)
    {

      if (File.Exists(file) == true)// 不同于目录Directory
      {
        Console.WriteLine("数据库存在");

      }
      else
      {
        SQLiteConnection.CreateFile(file);
      }
    }

    //sql格式要为CREATE TABLE IF NOT EXISTS
    /// <summary>
    /// 创建表格
    /// </summary>
    /// <param name="sql">建表语句</param>

    public static void CreateTable(string sql)
    {
      SQLiteConnection conn = new SQLiteConnection(connectionString);

      conn.Open();
      SQLiteCommand command = new SQLiteCommand(sql, conn);
      command.ExecuteNonQuery();

    }


    #endregion

    #region 公用方法

    public static int GetMaxID(string FieldName, string TableName)
    {
      string strsql = "select max(" + FieldName + ")+1 from " + TableName;
      object obj = GetSingle(strsql);
      if (obj == null)
      {
        return 1;
      }
      else
      {
        return int.Parse(obj.ToString());
      }
    }
    public static bool Exists(string strSql)
    {
      object obj = GetSingle(strSql);
      int cmdresult;
      if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
      {
        cmdresult = 0;
      }
      else
      {
        cmdresult = int.Parse(obj.ToString());
      }
      if (cmdresult == 0)
      {
        return false;
      }
      else
      {
        return true;
      }
    }
    public static bool Exists(string strSql, params SQLiteParameter[] cmdParms)
    {
      object obj = GetSingle(strSql, cmdParms);
      int cmdresult;
      if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
      {
        cmdresult = 0;
      }
      else
      {
        cmdresult = int.Parse(obj.ToString());
      }
      if (cmdresult == 0)
      {
        return false;
      }
      else
      {
        return true;
      }
    }

    #endregion

    #region  执行简单SQL语句

    /// <summary>
    /// 执行SQL语句，返回影响的记录数
    /// </summary>
    /// <param name="SQLString">SQL语句</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSql(string SQLString)
    {
      using (SQLiteConnection connection = new SQLiteConnection(connectionString))
      {
        using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
        {
          try
          {
            connection.Open();
            int rows = cmd.ExecuteNonQuery();
            return rows;
          }
          catch (System.Data.SQLite.SQLiteException E)
          {
            connection.Close();
            throw new Exception(E.Message);
          }
        }
      }
    }

    /// <summary>
    /// 执行多条SQL语句，实现数据库事务。
    /// </summary>
    /// <param name="SQLStringList">多条SQL语句</param>		
    public static void ExecuteSqlTran(ArrayList SQLStringList)
    {
      using (SQLiteConnection conn = new SQLiteConnection(connectionString))
      {
        conn.Open();
        SQLiteCommand cmd = new SQLiteCommand();
        cmd.Connection = conn;
        SQLiteTransaction tx = conn.BeginTransaction();
        cmd.Transaction = tx;
        try
        {
          for (int n = 0; n < SQLStringList.Count; n++)
          {
            string strsql = SQLStringList[n].ToString();
            if (strsql.Trim().Length > 1)
            {
              cmd.CommandText = strsql;
              cmd.ExecuteNonQuery();
            }
          }
          tx.Commit();
        }
        catch (System.Data.SQLite.SQLiteException E)
        {
          tx.Rollback();
          throw new Exception(E.Message);
        }
      }
    }

    /// <summary>
    /// 执行带一个存储过程参数的的SQL语句。
    /// </summary>
    /// <param name="SQLString">SQL语句</param>
    /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSql(string SQLString, string content)
    {
      using (SQLiteConnection connection = new SQLiteConnection(connectionString))
      {
        SQLiteCommand cmd = new SQLiteCommand(SQLString, connection);
        SQLiteParameter myParameter = new SQLiteParameter("@content", DbType.String);
        myParameter.Value = content;
        cmd.Parameters.Add(myParameter);
        try
        {
          connection.Open();
          int rows = cmd.ExecuteNonQuery();
          return rows;
        }
        catch (System.Data.SQLite.SQLiteException E)
        {
          throw new Exception(E.Message);
        }
        finally
        {
          cmd.Dispose();
          connection.Close();
        }
      }
    }

    /// <summary>
    /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
    /// </summary>
    /// <param name="strSQL">SQL语句</param>
    /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
    {
      using (SQLiteConnection connection = new SQLiteConnection(connectionString))
      {
        SQLiteCommand cmd = new SQLiteCommand(strSQL, connection);
        SQLiteParameter myParameter = new SQLiteParameter("@fs", DbType.Binary);
        myParameter.Value = fs;
        cmd.Parameters.Add(myParameter);
        try
        {
          connection.Open();
          int rows = cmd.ExecuteNonQuery();
          return rows;
        }
        catch (System.Data.SQLite.SQLiteException E)
        {
          throw new Exception(E.Message);
        }
        finally
        {
          cmd.Dispose();
          connection.Close();
        }
      }
    }

    /// <summary>
    /// 执行一条计算查询结果语句，返回查询结果（object）。
    /// </summary>
    /// <param name="SQLString">计算查询结果语句</param>
    /// <returns>查询结果（object）</returns>
    public static object GetSingle(string SQLString)
    {
      using (SQLiteConnection connection = new SQLiteConnection(connectionString))
      {
        using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
        {
          try
          {
            connection.Open();
            object obj = cmd.ExecuteScalar();
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
              return null;
            }
            else
            {
              return obj;
            }
          }
          catch (System.Data.SQLite.SQLiteException e)
          {
            connection.Close();
            throw new Exception(e.Message);
          }
        }
      }
    }

    /// <summary>
    /// 执行查询语句，返回SQLiteDataReader
    /// </summary>
    /// <param name="strSQL">查询语句</param>
    /// <returns>SQLiteDataReader</returns>
    public static SQLiteDataReader ExecuteReader(string strSQL)
    {
      SQLiteConnection connection = new SQLiteConnection(connectionString);
      SQLiteCommand cmd = new SQLiteCommand(strSQL, connection);
      try
      {
        connection.Open();
        SQLiteDataReader myReader = cmd.ExecuteReader();
        return myReader;
      }
      catch (System.Data.SQLite.SQLiteException e)
      {
        throw new Exception(e.Message);
      }

    }

    /// <summary>
    /// 执行查询语句，返回DataSet
    /// </summary>
    /// <param name="SQLString">查询语句</param>
    /// <returns>DataSet</returns>
    public static DataSet Query(string SQLString)
    {
      using (SQLiteConnection connection = new SQLiteConnection(connectionString))
      {
        DataSet ds = new DataSet();
        try
        {
          connection.Open();
          SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
          command.Fill(ds, "ds");
        }
        catch (System.Data.SQLite.SQLiteException ex)
        {
          throw new Exception(ex.Message);
        }
        return ds;
      }
    }


    #endregion

    #region 执行带参数的SQL语句

    /// <summary>
    /// 执行SQL语句，返回影响的记录数
    /// </summary>
    /// <param name="SQLString">SQL语句</param>
    /// <returns>影响的记录数</returns>
    public static int ExecuteSql(string SQLString, params SQLiteParameter[] cmdParms)
    {
      using (SQLiteConnection connection = new SQLiteConnection(connectionString))
      {
        using (SQLiteCommand cmd = new SQLiteCommand())
        {
          try
          {
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);
            int rows = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return rows;
          }
          catch (System.Data.SQLite.SQLiteException E)
          {
            throw new Exception(E.Message);
          }
        }
      }
    }


    /// <summary>
    /// 执行多条SQL语句，实现数据库事务。
    /// </summary>
    /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SQLiteParameter[]）</param>
    public static void ExecuteSqlTran(Hashtable SQLStringList)
    {
      using (SQLiteConnection conn = new SQLiteConnection(connectionString))
      {
        conn.Open();
        using (SQLiteTransaction trans = conn.BeginTransaction())
        {
          SQLiteCommand cmd = new SQLiteCommand();
          try
          {
            //循环
            foreach (DictionaryEntry myDE in SQLStringList)
            {
              string cmdText = myDE.Key.ToString();
              SQLiteParameter[] cmdParms = (SQLiteParameter[])myDE.Value;
              PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
              int val = cmd.ExecuteNonQuery();
              cmd.Parameters.Clear();

              trans.Commit();
            }
          }
          catch
          {
            trans.Rollback();
            throw;
          }
        }
      }
    }


    /// <summary>
    /// 执行一条计算查询结果语句，返回查询结果（object）。
    /// </summary>
    /// <param name="SQLString">计算查询结果语句</param>
    /// <returns>查询结果（object）</returns>
    public static object GetSingle(string SQLString, params SQLiteParameter[] cmdParms)
    {
      using (SQLiteConnection connection = new SQLiteConnection(connectionString))
      {
        using (SQLiteCommand cmd = new SQLiteCommand())
        {
          try
          {
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);
            object obj = cmd.ExecuteScalar();
            cmd.Parameters.Clear();
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
              return null;
            }
            else
            {
              return obj;
            }
          }
          catch (System.Data.SQLite.SQLiteException e)
          {
            throw new Exception(e.Message);
          }
        }
      }
    }

    /// <summary>
    /// 执行查询语句，返回SQLiteDataReader
    /// </summary>
    /// <param name="strSQL">查询语句</param>
    /// <returns>SQLiteDataReader</returns>
    public static SQLiteDataReader ExecuteReader(string SQLString, params SQLiteParameter[] cmdParms)
    {
      SQLiteConnection connection = new SQLiteConnection(connectionString);
      SQLiteCommand cmd = new SQLiteCommand();
      try
      {
        PrepareCommand(cmd, connection, null, SQLString, cmdParms);
        SQLiteDataReader myReader = cmd.ExecuteReader();
        cmd.Parameters.Clear();
        return myReader;
      }
      catch (System.Data.SQLite.SQLiteException e)
      {
        throw new Exception(e.Message);
      }

    }

    /// <summary>
    /// 执行查询语句，返回DataSet
    /// </summary>
    /// <param name="SQLString">查询语句</param>
    /// <returns>DataSet</returns>
    public static DataSet Query(string SQLString, params SQLiteParameter[] cmdParms)
    {
      using (SQLiteConnection connection = new SQLiteConnection(connectionString))
      {
        SQLiteCommand cmd = new SQLiteCommand();
        PrepareCommand(cmd, connection, null, SQLString, cmdParms);
        using (SQLiteDataAdapter da = new SQLiteDataAdapter(cmd))
        {
          DataSet ds = new DataSet();
          try
          {

            da.Fill(ds, "ds");
            cmd.Parameters.Clear();
          }
          catch (System.Data.SQLite.SQLiteException ex)
          {
            throw new Exception(ex.Message);
          }
          return ds;
        }
      }
    }


    private static void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, SQLiteTransaction trans, string cmdText, SQLiteParameter[] cmdParms)
    {
      if (conn.State != ConnectionState.Open)
        conn.Open();
      cmd.Connection = conn;
      cmd.CommandText = cmdText;
      if (trans != null)
        cmd.Transaction = trans;
      cmd.CommandType = CommandType.Text;//cmdType;
      if (cmdParms != null)
      {
        foreach (SQLiteParameter parm in cmdParms)
          cmd.Parameters.Add(parm);
      }
    }

    #endregion



  }
}
